Question about 2008 Chevrolet Silverado 1500 2WD

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Po449 and455 code what is this

Check engine light goes off then comes back on vehicle run great what can i do to fix the problem

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Possible loose gas cap. Tighten cap and disconnect negative battery cable for about 15 min and reconnect to clear error.

Posted on Apr 21, 2014

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Go to It shows you how to replace the Evap Valve which causes these codes. . It is simple to do. Hope this helps you. Buy from Amazon or other online store. You will save money .

Posted on Apr 21, 2014

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SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
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Posted on Jan 02, 2017

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SOURCE: 2001 chevy impala

You might get some gas treatment for your tank. Sometimes bad gas can cause those symptoms.
I would put the treatment in and let it sit overnight. Hopefully the next morning the car will feel better!
I hope this helps... Good luck!

Posted on Sep 24, 2009

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SOURCE: truck runs great but the oil pressure gage goes zeros out

Did you find the sending unit and was that the problem?

Posted on Nov 21, 2009

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SOURCE: 2002 GMC Z-71 Check Engine Light codes????

maf or vac circuit low
purge/vac vent valve malfuntion
if your purge valve were stuck open it would cause a rich condition because it would constantly be sucking gas fumes from the tank. repair the evap. purge system first then go on to the other code
the purge solonoid is connected to the evap canister it cycles on and off the rapidly to remove gas vapor from the fuel tank system. it is usually near a plasitic tee fitting with a green cap on one of the legs off the tee. when the engine is warmed up it should make a audible tick tick tick sound.sometimes a piece of the carbon breaks loose from the carbon canister and blocks open the purge valve.if carbon in valve replace canister and clean/replace purge valve.

Posted on Mar 30, 2010

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when run with a misfire, the cat will get loaded up with fuel, it takes awhile for it to burn out, and a code may set, on some occasions it ruins the converter, try clearing it and running it

Posted on Oct 14, 2010

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SOURCE: getting an error code of PO449 for a check engine

You are right. You need the vent valve not the purge valve. The vent valve is a dealer item. Also this is a common problem and GM has released a bulletin on this that involves moving the location of the valve and running some new lines. It comes as a kit from GM, and it costs about a 100 bucks.

Posted on Dec 02, 2010

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2008 chevy cobalt engine light on

Your Po449 code means: Evaporative Emission (EVAP) Vent Solenoid Control Circuit. Check to see if anything on you EVAP system has gotten disconnected and make sure that none of your hoses have gotten old and bridle or have holes. If everything looks ok, you probably have to replaced the Vent Solenoid Valve, which is located on the EVAP canister.

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2005 chevy Z71 check engine code PO449 and PO455 5.3 Lt engine how do i fix them

get a new gas cap your evap sytem isnt working if the gas cap doesnt work then you might have a leak and check your EVAP purge valaves

Dec 07, 2011 | Cars & Trucks

1 Answer

Check engine light came on giving me the code po449 when i had them put it on the machine

I do not have the PO449 code,but it is in with
the EVAP System codes
You will need professional help with EVAP Leaks,
only because they are so small, and there are a lot
of components in the system
So an EVAP Smoke Machine is used to find them.
It is about $1100 piece of equip. Fairly cheap and
fast at finding your problems.
Also a scanner may be necessary to actuate components
That is 9 grand plus 2 g for software.

No one ever puts a machine or computer on your vehicle,ever.
What is used, is a code reader or scan tool,to look at your
vehicles ECM or PCM. Your vehicle, is more of an assortment
of processors,than computers.

Dec 04, 2010 | 2006 Chevrolet Impala

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The check engine light comes on from time to time, goes off some of the time, has little shake when first starts, but otherwise runs fine

When a check engine light comes on, even if it goes off, it still sets a code that stays in the vehicles computer. I suggest taking your vehicle to Autozone(or similar part store) and take advantage of their free computer diagnosis. They can print you off a receipt with the codes as well as the most likely causes and solutions. This would be a great starting point.

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Engine light on cleared and came back on

Evap Codes.You got the codes. Leaks. Now check the entire system. May be a cracked or loose hose. If not,check valves,switches.solenoids. If nothing you can find or are familiar with on site,you will need professional help and possibly a pressure test,vacuum test, smoke test etc,to find the problem.

Mar 31, 2010 | 2002 Chrysler Town & Country

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Check engine light on 2004 GMC Yukon XL

Code po449 is the canister vent valve solenoid error.This is a common problem with these valves because they are under the truck in the rear by the spare tire and they get all the dirt and water and snow,if you live in an area where you get snow.You will find it on the canister under the vehicle by the spare tire.

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2005 chevy cobalt 37.000 miles engine light on. Code is obdIIpo449b any idea what it is the car runs great


Aug 28, 2009 | 2005 Chevrolet Cobalt

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Check engine light comes on but car runs great 2002 bmw 325i and

The check engine light could be any number of things and the only way to find out is have the codes scanned. The brake light issue is common on E46 3 series. It is an issue were the brown ground wire that goes into the lamp housing melts at the connector causing a loose ground connection. The connector needs to be replaced and also add additional grounding wires to prevent further issues. And for fuel additives either use the cheveron techron, or the bmw fuel additive(the bmw stuff is the exact same thing, so just use which ever is cheaper).

Mar 10, 2009 | 2001 BMW 325

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